Installed stereo, lost speedometer & cruise

I recently bought a 1999 Malibu, The previous owner had taken out their stereo and cut the wiring. I already found the diagram on 12volt to color coding for audio wiring. I set out to install it and got everything working, had music and all speakers seemed to be working but when I went to slide it into the dash the stereo quit working. The next day I realized that my speedometer and cruise went out. On the drive home I turned on my headlights and the radio came on and speedometer started working. I am at a loss for a cure. Any help out there?

PS, the stereo lights come on but I do not get audio besides a crackling from the rear speakers.

Sounds like the 12v you tapped is controlled by the headlight switch. Lots of times the colors don't mean anything year to year. You'll need a voltmeter. http://www.installdr.com/
Edit: You need a constant 12v for saving memory, etc. Then a switchable 12v, normally wire off ignition switch. Also, 12v lighting/illuminating.

Thank you, I will follow up when I get off work today.